Synchronization Performance Of The Multi-channel Data Acquisition System Based On Pci Bus

Utilizing receiving antenna arrays allocated in large area to form a large antenna aperture, the large antenna arrays imaging radar obtains high aspect resolution. Receiving modules in the array receive target's echo and array signal processing put a requirement on channel's synchronization. Thus, a strict synchronization requirement is also put on system's multi-channel data acquisition sets. Related applications, including large antenna arrays imaging radar, have a higher requirement on multi-channel data acquisition set's synchronization design and testing. This dissertation discusses method to evaluate the delay of channels, and focuses on sine-wave fitting procedure. This dissertation also provides analysis on uncertainty evaluation of delay between channels.Sine-wave fitting method is widely used in signal processing field. Counting on convergence performance, non-linear RLS algorithm based on one-dimensional searching is used in my research. Simulation results proved that it has faster convergence rate.The testing platform was a dual-channel data acquisition set based on PCI bus with two piece of 100 MHz data acquisition card. My research also developed the application software under Microsoft Visual C++ 6.0 environment.Combined with sine-wave fitting method and the testing platform, my research evaluated the delay of channels, which is coherent with observation result. Through uncertainty analysis, we could find that this method had a higher precision than direct wave observation. This also proved that sine-wave fitting method is a kind of method which could precisely evaluate delay of channels.At last, the signals from IQ channels were sampled using the data acquisition set. Correction is made on the unbalance in amplitude, phase, and direct current. After correction, the residual phase between IQ channels is 3.0034×10^-5rad.